Peel and core 2/3 of the apples, core the remaining apples but leave the skin, cut apples into small slices, put into a blender with the other ingredients and purée.
Ricotta mousse: Mix the ricotta with icing sugar and lemon juice. Whisk the cream and egg whites separately until both are firm, then blend the whipped cream followed by the stiff egg whites into the ricotta mixture. Take a colander, line with a tea towel and place the mixture inside to strain. Chill in the refrigerator for 3 hours.
Serving:
Pour the apple soup into chilled soup plates, form small dumplings from the ricotta mousse using a tablespoon and garnish with dumplings as desired.